Conduit coupling system, tool and method

ABSTRACT

A system for coupling conduit sections includes a coupling tool with a pair of lever arms pivotally interconnected and each mounting a clamp assembly. The clamp assemblies are adapted for releasably clamping the conduit sections. A coupling has a generally tubular configuration with a throughbore with multiple annular internal ribs. A coupling method includes the steps of clamping first and second conduit sections with respective clamping assemblies, placing the conduit section ends against the coupling throughbore ends, and squeezing the tool lever arms together whereby the conduit section ends are inserted into the coupling throughbore in fluid-tight sealing and pull-out resistant engagement.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to conduit or pipe couplings,and in particular to a system, tool and method for pushing the ends of apair of plastic conduit sections into a coupling to form a fluid-tight,pull-out resistant coupling therebetween.

2. Discussion of the Related Art

Couplings and fittings of various types are used for joining pipes andconduits. Examples include threaded fittings, couplings that are securedwith solvent adhesives, weldments and various push-type couplings. Theperformance criteria for pipe coupling mechanisms are generallydetermined by such factors as the pipe materials, design pressures,temperature ranges, fluid-tight requirements, pull-out resistancerequirements and environmental conditions.

For example, the nationwide, fiber-optic, telecommunications networksconsist largely of buried fiber-optic cables. The cables are commonlyprotected from groundwater and other subsurface conditions by enclosingthem within plastic conduits. A common fiber-optic cable installationprocedure involves placing the empty conduits below grade with specialtrenching and tunnel-boring equipment, whereafter the fiber-optic cablesare blown through the conduit with high-pressure air. The plasticconduits and the connecting fittings used in such installations must beimpervious to groundwater, resistant to the corrosive effects of soiland capable of maintaining relatively high internal air pressures.Therefore, the connecting fittings or couplings used for joining theconduit sections require sufficient pull-out resistance to withstandinternal air pressures, and further to resist tensile forces tending toseparate the conduit sections by pulling apart their connections.

Conduit coupling systems are commonly used in adverse field andenvironmental conditions where only minimal equipment is available andspeed is relatively important. Therefore, machining and otherpreparation of the conduit sections ends should be eliminated orminimized. Manually-operated hand tools are generally preferred due totheir portability and independence from external power sources.Moreover, the couplings and other fittings should be relatively simple,inexpensive, strong and reliable. Still further, the bores of thealigned conduit sections should be free from obstructions after they arecoupled.

Heretofore there has not been available a conduit coupling system, tooland method with the advantages and features of the present invention.

BRIEF DESCRIPTION OF THE INVENTION

In the practice of one aspect of the present invention, a couplingsystem, tool and method are provided for continuously fluidicallyconnecting a pair of conduit sections with a coupling having internal,annular ribs adapted and oriented to pass the conduit section endsone-way into the coupling and to resist pull-out in the oppositedirection. The tool comprises a pivotally interconnected pair of leverarms each mounting a respective clamp assembly. Practicing an aspect ofthe method of the present invention involves clamping the conduitsections with the clamp assemblies, spreading the lever arms to theiropen position, placing a coupling between the conduit sections ends andclosing the lever arms whereby the conduit section ends are pushed intoand fixedly received in the coupling. Pull-out resistance is provided bythe coupling internal ribs, which impinge on the conduit sections forsecurely retaining same in fluid-tight engagement with the coupling.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constitute a part of this specification and includeexemplary embodiments of the present invention and illustrate variousobjects and features thereof.

FIG. 1 is a perspective view of a conduit coupling tool embodying anaspect of the present invention, with the conduit sections and thecoupling shown in phantom lines.

FIG. 2 is a front elevational view thereof.

FIG. 3 is a side elevational view thereof.

FIG. 4 is an enlarged, fragmentary, cross-sectional view of a clampassembly and the coupling, taken generally within circle 4 in FIG. 2 andshowing the conduit section ends in phantom lines and in position forinsertion into the coupling with the coupling tool in its open position.

FIG. 5 is an enlarged, front elevational view of the clamp assembly onthe left and a cross-sectional view of the clamp assembly on the rightand the coupling, with the conduit section ends fixedly embedded in thecoupling and the coupling tool in its closed position.

FIG. 6 is an enlarged, side elevational view of a clamp assembly takengenerally along line 6-6 in FIG. 4, with the clamp assembly in itsclosed position.

FIG. 7 is an enlarged, side elevational view of the clamp assembly inits open position with a conduit section being extracted therefrom.

DETAILED DESCRIPTION OF THE INVENTION

I. Introduction and Environment

As required, detailed embodiments and/or aspects of the presentinvention are disclosed herein; however, it is to be understood that thedisclosed embodiments/aspects are merely exemplary of the invention,which may be embodied in various forms. Therefore, specific structuraland functional details disclosed herein are not to be interpreted aslimiting, but merely as a basis for the claims and as a representativebasis for teaching one skilled in the art to variously employ thepresent invention in virtually any appropriately detailed structure.

Referring to the drawings in more detail, the reference numeral 2generally designates a coupling tool adapted for inserting the ends ofconduit sections 4, 6 into a tubular coupling 8. Without limitation onthe generality of useful applications of the coupling tool 2, theconduit sections 4, 6 can comprise various suitable plastics, such aspolyvinyl chloride (PVC) polyethylene, polypropylene, etc. The tool 2generally comprises a lever assembly 10 and a pair of clamp assemblies12 mounted thereon.

II. Coupling Tool 2

The lever assembly 10 comprises a pair of lever arms 13, 14, which arepivotally interconnected by a pivot connector 16. The lever arms 13, 14include respective, proximal handle ends 18, 20 and distal ends 22, 24,which mount the clamp assemblies 12.

Each clamp assembly 12 includes a stationary jaw 26 and a movable jaw 28movably mounted thereon by a hinge 30 attached to the undersides of thejaws 26, 28. The stationary jaw 26 is rotatably mounted on a respectivelever arm distal end 22 or 24 by an axle 32, with a coaxial rotationalaxis 34 extending perpendicularly from the lever arm distal end 22 or24. The axle 32 is fixedly retained in place in the stationary jaw 26 byan axle retainer screw 33, which extends through the hinge 30, the axle32 and into the stationary jaw 26 (FIGS. 6 and 7). The jaws 26, 28include respective engagement faces 36, 38 with respective conduitreceiver halves 40, 42. With the jaws 26, 28 closed, the receiver halves40, 42 are positioned in opposed relation to form a conduit receiver 44(FIG. 6). Each receiver half 40, 42 includes multiple, semi-circulararcuate receiver ribs 46 with sawtooth-shaped cross-sections formingengagement edges 48 adapted for grippingly engaging the conduit sections4, 6 (FIGS. 4 and 5).

The jaws 26, 28 include respective latch channels 52, 54, whichpartially receive respective latch mechanisms 56 adapted for selectivelylatching and tightening the clamp assemblies 12. Each latch mechanism 56includes a latch bolt 58 with an inner, retained end 60 mounting a crosspin 62 pivotally received in respective cross pin receivers 64 locatedon opposite sides of the stationary jaw 26 and its latch channel 52.Each latch bolt includes a threaded outer end 66 threadably mounting aknurled nut 68 adapted for manual tightening whereby the clamp assembly12 securely clamps a respective conduit sections 4 or 6. An alignmentmechanism 70 interconnects the clamp assemblies 12 and includes analignment rod 72, which slidably extends through respective, transverseguide rod passages 74 formed in the stationary jaws 26. The rod 72includes opposite ends 76 protruding beyond the stationary jaws 26 andmounting retainers 78, which are adapted for limiting the range ofmotion of the lever arms 13 at their maximum spread (FIG. 2).

III. Coupling 8 and Operation

In operation, the tool 2 is adapted for inserting the ends of theconduit sections 4, 6 into the coupling 8. The coupling 8 includes athroughbore 80 with first and second sections 81, 82, which areseparated by an annular center stop 84 located approximately midwaythrough the throughbore 80. Each throughbore section 81, 82 includesmultiple, annular coupling ribs 86 with sawtooth-shaped cross-sectionalconfigurations, which are somewhat similar to the configurations of theclamp jaw receiver ribs 46 (FIGS. 4 and 5). The coupling ribs 86likewise define relatively sharp, annular engagement edges 88, withinside diameters D. 1, which are slightly less than outside diametersD.2 of the conduit sections 4, 6. The coupling 8 preferably comprises arelatively hard material, such as polycarbonate, whereby the couplingrib edges 88 impinge on the conduit section outer surfaces, forming afluid-tight, pull-out resistant sealing connection therebetween. Thecoupling 8 can comprise a transparent or translucent plastic materialadapted for visual observation of the conduit section ends within thecoupling. The contents of the conduits, such as fiber-optic cables,fluids and the like, can also be observed through a clear, see-throughcoupling. Alternatively, the coupling 8 can comprise another suitablematerial, such as metal. The sawtooth configuration of the coupling ribs86 functions to permit one-way passage of the conduit sections 4, 6 intothe coupling throughbore 80, while resisting pull-out in the oppositedirection.

The conduit sections 4, 6 are placed in the clamp receivers 44 with theclamp assemblies 12 opened (FIG. 7), whereafter the clamp assemblies 12are securely clamped on the conduit sections 4,6 by tightening the latchmechanism nuts 68 (FIG. 6) whereby the engagement edges 48 of thereceiver ribs 46 impinge on the conduit sections 4, 6. With the leverassembly 10 in its closed position, the conduit sections 4, 6 can beproperly positioned in the clamp assemblies 12 with their ends touchingor nearly touching. The lever assembly 10 is then spread to provideclearance between the conduit section ends for the coupling 8 (FIGS. 2and 4). The lever assembly 10 provides considerable leverage wherebysubstantial compressive forces can be applied for securely embedding theconduit section ends in the respective throughbore first and secondsections 81, 82. The sawtooth configurations of the clamp receiver ribs46 function to effectively resist slippage of the captured conduitsections 4,6 and effectively transmit compressive forces, which insertthe conduit section ends into the coupling 8. The alignment mechanism 70rotates the clamp assemblies 12 on the lever arms 13, 14 about therotational axes 34 whereby the clamp assembly conduit receivers 44 aremaintained in axial alignment with the conduit sections 4, 6 and thecoupling 8.

It will be appreciated that the pull-out resistant coupling can beconfigured in various alternative aspects and embodiments within thescope of the present invention. For example, the tool 2 can be adaptedfor connecting conduit sections with various other types of fittings,such as reducers, Ts, elbows, etc. Moreover, external hydraulic,electrical or other power sources can be utilized for opening andclosing the clamp assemblies.

1. A system for coupling a conduit section, which includes: a couplingwith an end, a bore open at the end and an annular rib located withinthe bore; a coupling tool including a clamp assembly with a closedposition adapted for clamping the conduit section inside the clampassembly and an open position adapted for releasing the conduit section;and said coupling tool further including a push mechanism adapted forpushing the conduit section into the coupling bore in engagement withthe rib.
 2. The coupling system according to claim 1 wherein said pushmechanism includes: a pair of lever arms each having a proximal handleend and a distal end; said lever arms being pivotally interconnectedintermediate their respective ends; and a pair of said clamp assemblieseach mounted on a respective lever arm distal end.
 3. The couplingsystem according to claim 2 wherein each said clamp assembly includes: astationary jaw mounted on a respective lever arm distal end; a movablejaw hingedly mounted on said stationary jaw; a conduit receivercomprising first and second receiver portions each located on arespective jaw; and said movable jaw being pivotable between an openposition with said receiver portions spaced apart from each other and aclosed position with said receiver portions in opposed relation andforming said conduit receiver.
 4. The coupling system according to claim3 wherein each said conduit receiver includes an annular rib with asawtooth-shaped cross-sectional configuration sloping towards theinterior of said coupling tool and including an engagement edge adaptedfor engaging said conduit.
 5. The coupling system according to claim 3wherein each said clamp assembly includes: a latch mechanism with afirst component mounted on one of said jaws and a second componentadapted for tightening on said first component and selectively engagingsaid movable jaw and retaining same in its closed position.
 6. Thecoupling system according to claim 5 wherein: said stationary jaw andsaid movable jaw include respective latch channels, which align witheach other with said clamp assembly in its closed position; said firstcomponent comprises a threaded latch bolt pivotally mounted on saidstationary jaw and located in said latch channels with said clampassembly in its closed position; and said second component comprising anut threadably mounted on said bolt and selectively engaging saidmovable jaw with said clamp assembly in its closed position.
 7. Thecoupling system according to claim 2, which includes: each said clampassembly including a transverse passage; and an alignment rod extendingthrough said transverse passages and slidable with respect to at leastone of said clamp assemblies, said alignment rod being adapted foraligning said clamp assemblies through the opening and closing of saidcoupling tool.
 8. The coupling system according to claim 2 wherein saidcoupling includes: a generally cylindrical tubular configuration withopposite ends and said coupling bore extending between and open at saidends; said coupling bore having first and second sections adjacent saidcoupling ends respectively; and each said coupling bore section havingmultiple said annular coupling ribs with sawtooth-shaped cross-sectionalconfigurations sloping inwardly and including annular engagement edgesadapted for passing said conduit sections into said coupling throughsaid coupling opposite ends and retaining same therein.
 9. The couplingsystem according to claim 2, which includes: a pair of axles eachmounted in a respective lever arm distal end and rotatably mounting arespective clamp assembly, each said axle defining a respectiverotational axis extending from front-to-back with respect to said tool.10. The coupling system according to claim 1 wherein said couplingcomprises a transparent or translucent material.
 11. The coupling systemaccording to claim 1 wherein said coupling comprises polycarbonatematerial.
 12. A system for coupling first and second conduit sections,which includes: a coupling with a generally cylindrical tubularconfiguration with opposite ends and a coupling bore extending betweenand open at said ends; said coupling bore having first and secondsections adjacent said coupling ends respectively; and each saidcoupling bore section having multiple said annular coupling ribs withsawtooth-shaped cross-sectional configurations sloping inwardly andincluding annular engagement edges adapted for passing said conduitsections into said coupling through said coupling opposite ends andretaining same therein, said coupling bore including an annular stoplocated medially therein; a coupling tool including a pair of lever armseach having a proximal handle end and a distal end; said lever armsbeing pivotally interconnected intermediate their respective ends; saidcoupling tool further including a pair of clamp assemblies each having aclosed position adapted for clamping a respective conduit section insidethe clamp assembly and an open position adapted for releasing theconduit section; each said clamp assembly including a stationary jawmounted on a respective lever arm distal end, a movable jaw hingedlymounted on said stationary jaw and a conduit receiver comprising firstand second receiver portions each located on a respective jaw; each saidmovable jaw being pivotable between an open position with said receiverportions spaced from each other and a closed position with said receiverportions in opposed relation and forming said conduit receiver; eachsaid conduit receiver including multiple annular ribs each having asawtooth-shaped cross-sectional configuration sloping towards theinterior of said coupling tool and including an engagement edge adaptedfor engaging said conduit; each said clamp assembly including a latchmechanism with a first component mounted on one of said jaws and asecond component adapted for tightening on said first component andselectively engaging said movable jaw and retaining same in its closedposition; each said stationary jaw and said movable jaw includingrespective latch channels, which align with each other when said clampassembly in its closed position each said clamp assembly including alatch mechanism with a first component mounted on one of said jaws and asecond component adapted for tightening on said first component andselectively engaging said movable jaw and retaining same in its closedposition, said first component comprising a threaded latch boltpivotally mounted on said stationary jaw and located in said latchchannels with said clamp assembly in its closed position and said secondcomponent comprising a nut threadably mounted on said bolt andselectively engaging said movable jaw with said clamp assembly in itsclosed position; each said clamp assembly including a transversepassage; said coupling tool including an alignment rod with oppositeends and extending through said transverse passages and slidable withrespect to at least one of said clamp assemblies, said alignment rodbeing adapted for aligning said clamp assemblies through the opening andclosing of said coupling tool; a pair of alignment rod retainers eachmounted on a respective alignment rod end; and said coupling toolincluding a pair of axles each mounted in a respective lever arm distaland rotatably mounting a respective clamp assembly, each said axledefining a respective rotational axis extending from front-to-back withrespect to said tool.
 13. A method of coupling a conduit section, whichincludes the steps of: providing a coupling with an end and a bore openat the end; providing an annular rib in said coupling bore; providing acoupling tool with a clamp assembly; providing said coupling tool with apush mechanism; clamping said conduit section in said clamp assembly;pushing said conduit section into said coupling bore with said pushmechanism; engaging said conduit section with said coupling rib; andreleasing said conduit section from said clamp assembly.
 14. The methodaccording to claim 13, which includes the additional steps of: providingsaid coupling tool with a pair of lever arms each having a proximalhandle end and a distal end; pivotally interconnecting said lever armsintermediate their respective ends; providing a pair of said clampassemblies and mounting each on a respective lever arm distal end;spreading said lever arms to an open position of said tool; clampingfirst and second conduit sections with said first second clampassemblies respectively; placing said coupling between said conduitsections; closing said lever arms; pushing said conduit sections intosaid coupling bore; and releasing said conduit sections from said clampassemblies.
 15. The method according to claim 14, which includes theadditional steps of: providing each said clamp assembly with astationary jaw and mounting same on a respective lever arm distal end;providing each said clamp assembly with a movable jaw and hingedlymounting same on a respective stationary jaw; providing each said clampassembly with a conduit receiver comprising first and second receiverportions each located on a respective jaw; placing said conduit sectionsin said conduit receivers; and pivoting said movable jaws on said clampassembly to close same on said conduit sections.
 16. The methodaccording to claim 14, which includes the additional steps of: providingeach said conduit receiver with multiple annular ribs each having asawtooth-shaped cross-sectional configuration sloping towards theinterior of said coupling tool and providing each said ridge with anengagement edge; engaging each said conduit section with a respectivesaid rib engagement edge; and preventing one-way slippage between eachsaid conduit section and a respective clamp mechanism with a respectivesaid ridge.
 17. The method according to claim 15, which includes theadditional steps of: providing each said stationary jaw and movable jawwith respective latch channels; aligning said latch channels with eachother when said clamp assemblies are in their closed positions;providing each said clamp assembly with a latch mechanism including afirst component mounted on one of said jaws and a second component;tightening said second complements on said first components and engagingsaid movable jaws; and retaining said movable jaws in their closedpositions.
 18. The method according to claim 17, which includes theadditional steps of: providing threaded latch bolts for said firstcomponents and pivotally mounted same on said stationary jaws; locatingsaid latch bolts in respective latch channels with said clamp assembliesin their closed positions; and providing nuts for said secondcomponents; threadably mounting said nuts on said bolts and engagingsaid movable jaws with said nuts for retaining same in their closedpositions.
 19. The method according to claim 14, which includes theadditional steps of: providing each said clamp assembly with arespective transverse passage; and providing said coupling tool with analignment rod extending through said transverse passages and slidablewith respect to at least one of said clamp assemblies, said alignmentrod being adapted for aligning said clamp assemblies through the openingand closing of said coupling tool.
 20. The method according to claim 13,which includes the additional step of: forming said coupling fromtransparent or translucent polycarbonate material.